This invention relates to a drive shaft of a motor vehicle, and, more particularly, it is concerned with a device for attenuating vibrations in the drive shaft of a vehicle especially for a front-engine-front-drive system, or a rear-engine-rear-drive system.
These types of motor vehicles are of such construction that the driving force of the engine is transmitted to the left and right drive shafts through the clutch, the transmission mechanism, and the differential gears to thereby drive the wheels. In such construction, vibrations generated from the engine, vibrations due to torque variations, and vibrations taken place by other causes tend to propagate to the drive shaft more easily than in the motor vehicle of a type, wherein a propeller shaft is employed as in a front-engine-rear-drive system which is commonly adopted in motor vehicles in general. As the result of such propagation of the vibrations, the drive shaft becomes resonant in some occasion.
When the resonance of the above-mentioned drive shaft occurs within a range of practical numbers of revolution of the engine, the vibrations caused thereby propagate to the vehicle body from the knuckle arm through the shock absorbers, springs, and other component parts to produce sound of resonance within the vehicle cabin to give disagreeable feeling to a vehicle driver and occupants.